Conventional cochlear implant systems include various components configured to be implanted within a patient (e.g., a cochlear implant, an antenna, and an electrode lead) and various components configured to be located external to the patient (e.g., a sound processor, a battery, and a microphone). Unfortunately, the external components of a conventional cochlear implant system are often relatively large, bulky, and aesthetically unpleasing. Hence, various fully implantable cochlear implant systems have been described in which the sound processor and one or more other components typically located external to the patient (i.e., the battery and/or the microphone) are also implanted within the patient. In these configurations, the patient may enjoy cochlear implant functionality with little or no externally located components for various periods throughout the day.
Unfortunately, some patients cannot initially be fitted with a fully implantable cochlear implant system. For example, some patients (e.g., pediatric patients) may possess one or more physiological traits that may limit the number and/or size of components that may be implanted within their heads. Other patients may be unable to be fitted with a fully implantable cochlear implant system for technological, logistical, and/or financial reasons. Hence, these patients may be initially fitted with a conventional cochlear implant system. However, over time, they may become eligible for a fully implantable cochlear implant system. Such an upgrade would typically require a patient to undergo a surgical procedure in which all of the already implanted components of the conventional cochlear implant system are replaced with the new fully implantable cochlear implant system components. In addition to being invasive and costly, this surgical procedure could potentially cause damage to one or more of the patient's auditory structures and thereby negate any benefits that could be provided by the fully implantable cochlear implant system.